Aquatic ski of different gender, in which a first kind includes essentially two longitudinal floating elements being over each one a place for foot are instead known. The enlivening of said ski is made by the user who, acting with the arms movement imprints laterally a pushing force as floating rackets. Being this solution totally afunctional, in a further solution, the foot seat is substantially modified realizing an anterior hinging, of the kind of the usual on ground ski, allowing better utilization of muscular force and increased speed.
Further solution is disclosed in U.S. Pat. No. 3,833,956 (John F. Mehan) in which a water skate for each foot including a buoyant hull structure is disclosed. Each hull has a vertically pivotable foot support mounted within a well in the hull. Movement of the foot support actuates a lever arm which is fixedly secured to the foot support and extends rearwardly beneath the hull and terminates in a horizontally disposed blade. The blade reciprocates through the water as it is moved by the pivotal movement of the foot support and reacts with the water to provide forward movement of the hull on both the upward and downward motion.
This solution provides an efficient propulsion of advancement without needing advancement arm propulsion means, nevertheless, the proposed propulsion means are not so efficient providing an effective resistance in the respective movement of its propulsion blade.
FR-A1-2481939 (COMPARON JEAN DANIEL) discloses downwards fixed hinged blades acting like fish fins that oscillates from a position parallel to the bottom of the hull to a more or less inclined position to realize resistance in the water in rear direction, the apparatus being further inflatable and foldable by intermediate hinging in order to store it in a reduced dimension. This solution is simpler than the first one but the sole rearward movement is not sufficient to realize a real reaction in advancement, because a certain "Hysteresis" happens before the resistance realized by the open blades transmit their reaction. For this reasons such solutions have not satisfied the exigencies of an appreciable utilization.